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29 January 2001 <br /> AGE-NC Project No 00-0725 <br />' Page 7 of 1 I <br />' 3 11 GROUND WATER SAMPLE COLLECTION/ANALYSIS <br /> A water sample was collected from each well using the dedicated disposable plastic bailer from the <br />' purge procedure Immediately upon retrieval, samples were transferred into three 40-milliliter(ml) <br /> EPA-approved volatile organic analysis (VOA) vials containing 0 5 ml 18%hydrochloric acid as a <br /> sample preservative <br />' The samples were logged on a chain-of-custody form, stored in a chilled container and transported <br /> under chain-of-custody to MAI The ground water samples were analyzed for selected constituents <br /> listed in Section 3 3 <br />' 312 SURVEYING <br /> On 02 February 2001, a California state-licensed survey engineer from Baumbach & Piazza, Inc <br /> surveyed a reference point on the top of each ground water monitoring well at the site to the nearest <br /> 0 01-foot relative to the City of Tracy Bench Marks and Description at 52 58 feet above mean sea <br /> level (msl) The results of the monitoring well survey are contained in Table 3 The surveying report <br /> (Baumbach & Piazza) is presented in Appendix D <br /> t4.0. FINDINGS <br /> A discussion of laboratory results of soil samples collected during interim soil excavation <br /> procedures as well as an estimate of the total hydrocarbon mass removed are presented Ground <br /> water elevations were determined by subtracting the measured depths-to-water from the surveyed <br /> casing elevations Ground water flow directions were determmed by contouring the water elevations <br /> on a scaled site plan(Figure 3) The impact of the unauthorized release on soil and ground water was <br /> quantified by laboratory analysis of samples collected during the quarter <br /> I <br /> 41 STRATIGRAPHY <br /> The soil profile generally consisted of silt from surface grade to approximately 10 feet below surface <br /> grade Soil borings encountered a sand interval between 10 feet and above 15 feet bsg Silt was <br /> encountered in all borings at 15 feet bsg Saturated conditions were encountered at 10 feet bsg <br /> Ground water was present in the sand Petroleum hydrocarbon odor was noted in the samples <br /> collected mostly from the saturated or near saturated zone <br /> Advanced GeoEn viron mental,Inc <br />